Manufacture of pipes, tubes, and like hollow bodies.



. H. PARKER.

MANUFACTURE OF PIPES, TUBES, AND L IKE HOLLOW BODIES.

APPLICATION HLED APR. 1a. 1916. I

1 27121 1. Patented July 2, 1018.

FeL'nfiv-cemen) P1140 wound a Wound Bil/p Wound Paper wound zdp wauna' Mozdded 0 41 0 7 Paper wound spirafiy Papefwaundsplhq/{y or siraz'glv/ or 5,7847)? WITNESSES: I I N V EN TOR.

/) M //0Wara' l ar/rer:

I BY

k4; ATTORNEY.

ter described from pulp or paper.

' pulp was used, it was either formed under pressure in a mold, or a thin wet sheet just J as it comes from a web-forming, machine,

80 pear in the wall; an

*usmcrns 1mm OFFICE- Y nowmi) PARKER, oE BEEIQm, NEW HAMPSHIRE, ASSIGNOR 'IO BERLIN MILLS com- I 1mm, 0E ron'rmnn, MAINELA conronarron or MAINE.

MANUFACTURE 0E PIPES,

Specification of Letters Patent.

TUBES, AND LIKE HOLLOW BODIES.

Patented J uly 2, 1918.

I Application filed April19, 1916. 'Seria1No. 92,284.

.Bodies, ofwhich the following is a specifi-- cation.

It has been a well known practice heretofore to manufacture articles of the charac- When such as a cylinder mold, was Wound onto a mandrel until a proper thickness of wall was produced. In either case, afterthe tube was formed it was dried, and then usually subjected to an impregnating treatment as with a waterproofing or insulating compound. s

The winding process has been customarily used since it is less expensive .and produces a tube which is better in other respects thanthe molded tubes. 1

Past practice has shown that if the tube wall is too thick, or the drying process is carried on too rapidl laminations will ap- (l ifit is carried on too slowly the wall becomes porous. The impregnating process is done under heat, and it has been found that if the-wall is so thick as to require high temperature to drive the compound through the wall, the fibers are apt to be burned and the strength of the wall nfaterially diminished. These consid-- erations have necessitated keeping the thickness of the wall down to such, a point 40 that while the tubes are useful in a great many cases, such as conduit for electrical wiring, they are not; however, ada ted for any use in which they may be subjected to pressures of considerable amount, as for instance in the transmission of water and gas.

The tubes made by winding :1 narrow strip of paper spirall or a ,wide' strip strai ht, onto a man rel and. preferabliy treatlng the paper as it winds w1th an a hesive or waterproofing material, have very definite laminatmns which are liable to split and weaken the wall of .the tube. Tubesthus made are also quite brittle, and it is not possible to cut threads on them to take the ordinary forms of connections, such as unions, elbows, etc.

It is the purpose ofthis invention to produce pipes, tubes and other hollow bodies made from pulp or paper, or a combination of both,-'which shall have sufiicient strength to withstand the greater pressures to which pipes of larger sizes are subjected, and also .to providea new method of manufacturing such articles. I Broadly considered, my invention contemplates producing a pipe with a sectional. or compound wall, each section of which ma be formed and treated separately, and a l sections bound together into a homogeneous mass. I prefer to form each sectionby winding a web of wet pulp to the desired thickness, an outer section being formed directly on an inner section after the inner section has been dried and treated with the impregnating compound. But one or more of the sections may be formed of molded pulp or of wound paper treated as'it is wound, all of which will be more particularly described hereinafter.

In the drawings,

Figure 1 shows one type of a tube made which this first section is made is preferably of a low grade of inferior quality, which may not have great strength but is of such consistency that it will readily absorb the i;

impre atingcompound. 'The proper thickness 0 this wall above spoken of may mean \the maximum thickness which can be dried without causinglaminations and thoroughly impregnated without burning the fibers' It formed on it.

prevent its disintegration.

strength is desired the process can be carorder that all surfaces of the section may be subjected to the waterproofing process, and that after the Waterproofing process has been completed the section is again thoroughly dried.

The second or intermediate section is then formed directly onto the first section by winding thereon a web of pulp which ma be of the same or a better grade of stoc than that in the first section, and preferably the latter, having greater strength and less porosity. The thickness of this intermediate section is controlled by two considerations; first, that it may be thoroughly dried without causing laminations; and second, that it may be impregated either at a slightly lower temperature than that used in impregnating the first section, or for a shorter time, if the wall is of the same grade of stock and thickness as that ofthe inner section. In drying, this second section shrinks, binding itself securely onto the first section.

The second section being now dried and waterproofed, the third or outer section is This section may be of the same grade or stock as the second section, orof a still better and stronger stock. It must be of such a thickness that it can be thoroughly dried without causing laminations in itself or in the other sections, and that it may be impregnated without burning the fibers in any section. I It may not be necessary to impregnate this outer section throughout its entire thickness so long as the surface is impregnated to a suflicient depth to resist the effects of moisture and If additional ried further by adding additional sections; or an auxiliary reinforcement, such as wire, cord, or the like, can be wound onto one of the inner sections. In either or both of these ways a wall of great strength can be produced so that large pipes may bev made which are thoroughly practical for usefor heavy pressure service.

In Fig. 1, (1 denotes the complete tube, 6, c, .d, the inner, intermediate and outer sections respectively, and e the reinforcement which may or may not be used.

In Fig. 2, a denoting the pipe as a whole,

5 indicates the inner section formed from a.

narrow strip of paper spirally wound onto a mandrel until a wall of suflicient thickness has been built up, the paper preferably being treated as it is wound, and subjected to pressure to securely attach the successive layers together. Instead of a narrow strip wound spirally, a wide strip equal to the length of the finished tube may be used, and wound straight onto the mandrel.

After this inner section is dried and finished, the outer section 6 is formed directly thereon by winding a web of wet pulp to a proper thickness, as explained in connection with Fig. 1. This section is then dried, and in drying shrinks and binds itself onto the inner section, and it is then subjected to the impregnating treatment. Additional sections may be added as the case may require, having in mind the use to which the tube or pipe is to be put.

In Fig. 3 the pipe at comprises an inner tube is subjected to a compressive strain,

and where interior threaded connections are to be used.

The tube hereinabove described, with its wall strengthened by the addition of one or.

more sections, is adapted for use under pressures which the present types of pulp or paper tubes cannot withstand. Further-- more, the structural characteristics of the wall are such as to insure a long life to the tube without danger of its breaking down or disintegrating. And where the surface of the tube is formed by. winding a web of pulp onto an inner section, and then dried and impregnated, it is suitable to undergo machining operations such as tapering the ends as indicated in Fig. 1 for one type of a fitting, or threading the ends as indicated in Fig. 2' to take another type of fitting. This latter is an important feature made possible by the homogeneous character of the wall which results from the winding of the wet web of pulp, which is subsequently dried and impregnated It does not break or chip, and is not particularly brittle.

I wish it to be clearly understood that the terms used herein are terms of description and not of limitation, and that the invention is not necessarily limited to the manufacture of tubes, but may be of value in the manufacture of other structures.

I claim as my invention 1. A pipe, tube or the like.comprising aplurality of separate successively formed,

dried and impregnated tubular sections.

4. A pipe, tube or the like, made in part wall is strengthened by a covering of pulp amnion of pulp by winding a wet web of pulp onto a tubular section which had been previously formed, dried and impregnated, said wall of pulp after it is formed to proper thickness being dried and impregnated. v

5. A tube made from paper or pulp, and means for strengthening the wall thereof, said means comprising a suitably thick covering of pulp wound and shrunk onto said tube, and an impregnating material applied to said covering.

6. A pipe or tube of paper or pulp whose Wall is strengthened by a covering of pulp formed directly thereon and impregnated.

7. A pipe or tube of paper or pulp whose Wound and shrunk directly thereon, and an impregnating material applied to said covering.

8. That improvement in the manufacture of hollow bodies from pulp, which consists informing the wall in sections in the following manner: first, forming the inner section on a suitable mandrel and subjecting it to drying-and impregnating treatment; second, forming an additional sectiondirectly on the first section and subjecting it'to drying and impregnating treatment. A

9. A pulp pipe or like article, comprising a plurality of impregnated sections, one formed upon the other. I

10. That improvement in the manufacture of hollow bodies from pulp which consists in forming the Wall of a plurality of impregnated sections, one section directly on another, and impregnating an inner section before an outer section is formed thereon.

11. That improvement in the manufacture of hollow bodies from pulp which consists in the forming of a section of one grade of pulp, impregnating said section, then form ing a second section of a diflerent grade of pulp and impregnating that section.

12. That improvement in the manufacture of hollow tubular seamless bodies from pulp, which consists in winding onto a mandrel successive layers of wet ulp under pressure; next, in drying and impregnating said section; next, informing a second. section on said inner section and subjecting it to drying and impregnating treatment under conditions of time or temperature which are not in excess of those to which the inner section is subjected.

13. That improvement in the manufacture I of pipes, tubes or like articles from paper or pulp, which consists in forming, drying and impregnating one section; next, in forming a second section directly on the first section; and finally, in drying said second section and then subjecting it to treatment with an impregnating compound.

14. That improvement in the manufacture of pipes, tubes, or like articles, which consists, first in forming, drying and impregnating a section; next in forming a second section by Winding directly thereon a web of wet pulp; then,dr-ying said pulp; and finally subjecting it to treatment with an impregnating compound.

15. That improvement in the manufacture of hollow bodies from pulp, which consists in forming the wall in sections, one upon another, interposing between said sections a formed upon the other, an outer section shrunk onto an inner section.

18. That improvement in the'manufacture of hollow bodies from pulp which consists in forming the wall of a plurality of impregnated sections, one section directly on another, an outer section being shrunk onto an inner section after the said inner section has been impregnated.

19. That improvement in the manufacture of hollow bodies from pulp which consists in forming the wall ofa plurality of impregnated sections one on the other, the

said sections being made of diiferent grades of pulp, and an outer section shrunk on to an inner section. 1

HOWARD PARKER.

Witnesses:

E. (F. Benny,- ROBT. A. SMITH. 

